diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-21 04:18:23 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-21 04:18:23 +0300 |
| commit | 6e649d08568220ee88deef0a1ad8b3a935420cf2 (patch) | |
| tree | 421310a204dfa8477a2fd4afe15466ed078726c7 /arch | |
| parent | db77b8502a4071a59c9424d95f87fe20bdb52c3a (diff) | |
| parent | 3b4863fa5b7dd50dab1b10abbed938efd203752f (diff) | |
| download | linux-6e649d08568220ee88deef0a1ad8b3a935420cf2.tar.xz | |
Merge tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- rwsem micro-optimizations
- spinlock micro-optimizations
- cleanups, simplifications
* tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vduse: Remove include of rwlock.h
locking/lockdep: Remove lockdep_init_map_crosslock.
x86/ACPI/boot: Use try_cmpxchg() in __acpi_{acquire,release}_global_lock()
x86/PAT: Use try_cmpxchg() in set_page_memtype()
locking/rwsem: Disable preemption in all down_write*() and up_write() code paths
locking/rwsem: Disable preemption in all down_read*() and up_read() code paths
locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
locking/qspinlock: Micro-optimize pending state waiting for unlock
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/acpi/boot.c | 16 | ||||
| -rw-r--r-- | arch/x86/mm/pat/memtype.c | 4 |
2 files changed, 10 insertions, 10 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 907cc98b1938..4177577c173b 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -1840,23 +1840,23 @@ early_param("acpi_sci", setup_acpi_sci); int __acpi_acquire_global_lock(unsigned int *lock) { - unsigned int old, new, val; + unsigned int old, new; + + old = READ_ONCE(*lock); do { - old = *lock; new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1)); - val = cmpxchg(lock, old, new); - } while (unlikely (val != old)); + } while (!try_cmpxchg(lock, &old, new)); return ((new & 0x3) < 3) ? -1 : 0; } int __acpi_release_global_lock(unsigned int *lock) { - unsigned int old, new, val; + unsigned int old, new; + + old = READ_ONCE(*lock); do { - old = *lock; new = old & ~0x3; - val = cmpxchg(lock, old, new); - } while (unlikely (val != old)); + } while (!try_cmpxchg(lock, &old, new)); return old & 0x1; } diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index 46de9cf5c91d..004b37f026d1 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -159,10 +159,10 @@ static inline void set_page_memtype(struct page *pg, break; } + old_flags = READ_ONCE(pg->flags); do { - old_flags = pg->flags; new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags; - } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags); + } while (!try_cmpxchg(&pg->flags, &old_flags, new_flags)); } #else static inline enum page_cache_mode get_page_memtype(struct page *pg) |